Heater device

ABSTRACT

A heater device for heating objects, including a compartment having a heat generating material and a second compartment having an activation material to generate heat upon mutual contact. The compartments are adapted to present a heating surface to the object to be heated. A divider is positioned in the compartments forming a barrier to maintain separation between reaction components until opened by an opening member positioned in alignment with the divider. An access element is movable into contact with the barrier to permit a heat generating reaction there between.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a continuation-in-part of Heater Device applicationfiled Dec. 7, 2009, having Ser. No. 12/632,308, which is acontinuation-in-part of Heater Device application filed Jul. 22, 2008,having Ser. No. 12/220,146, which is a continuation-in-part of Pan InPan Heater application filed Oct. 4, 2007, having Ser. No. 11/973,178.

BACKGROUND

This invention relates to a device for heating the contents of acontainer and for keeping it warm. More particularly, the inventionrelates to a self-contained heater device that allows the contents suchas food in a container to be heated.

Often times, it is desirable to heat food and other items at a locationremote from a source of heat such as a stove or oven. Other times it isdesirable to take warmed or hot food and other items from the place ofheating to another location, such as a picnic, school or churchbasement, scout meeting and any of the myriad of events that do not meetor gather where heat is available. Sometimes the location is in alocation where fire is not permitted, such as a classroom or outdoorsduring the dry season. It is also important for military personnel tohave access to warm food, particularly when deployed in locations remotefrom their base or station.

One such self-contained warmer is disclosed in U.S. Patent ApplicationPublication No. US 2007/0034202, to Punphrey et al. in which a containerwith an exothermic composition is used to heat a vessel. A membrane isused to cover the exothermic composition, which is then activated byremoval of the membrane. Various compositions are disclosed that arebased on iron oxidation chemistry. The heater is in direct contact withthe container and must be put on a heat-resistant surface to be usedwithout damage.

U.S. Pat. No. 6,705,309 discloses a self-heating or self-coolingcontainer in which tubular walls defining an internal cavity into whichsteam or hot air is placed as a source of heat. This, of course,requires a source of that heated material.

It would be a great advantage if a way of heating containers could bedeveloped that has a controlled release of heat that is withinacceptable safety limits.

Another advantage would be to provide a way of heating containers thatproduces heat over an extended period of time, rather than simply havingan exothermic reaction that lasts a few minutes or less.

Yet another advantage would be to provide a way to activate heaters forcontainers that is simple and effective and that does not have thepotential for pre-activation.

Other advantages will appear hereinafter.

SUMMARY

The unique aspect of this invention is that a controlled, dispersedexothermic reaction can be used to heat the contents of a containerquickly and effectively while maintaining the heat for an extendedperiod of time. The heat generating reaction is activated by an accesselement that is not in position to cause the activation material tocontact the heat generating material until that is desired by the user.

In its simplest form, the present invention is a two component heaterthat has a surface on which objects can be heated upon activation of thetwo components to cause a heat generating reaction. Examples of objects,by way of example and not by way of limitation, that can be heated aretowels, wipes, cushions, hats, gloves and other apparel, food packagesand the like. The food package may be any package containing comestiblesor other material that is to be heated. Typical food boxes are what areknown in the military as MRE, which is an acronym for “meals ready toeat.”

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front elevation view of one component of the preferredembodiment of this invention.

FIG. 2 is a back elevational view of the embodiment of FIG. 1.

FIG. 3 is a sectional, side elevation view of the embodiment of FIG. 1taken along line 33.

FIG. 4 is a sectional view of a second component of the preferredembodiment of this invention.

FIG. 5 is a section view of the preferred embodiment of this inventionin FIG. 3, with the second component of FIG. 4, showing the device priorto activation.

FIG. 6 is a sectional view of the device of FIG. 5 after activation ofthe device.

FIG. 7 is a view of an object to be heated by the device of thisinvention.

DETAILED DESCRIPTION

The device, 10 generally in FIG. 1, includes a first compartment 11 anda second compartment 13, separated in this embodiment by a penetrabledivider 15 that keeps the contents of the compartments separated fromeach other. It is preferred that divider 15 have some thicknessseparating the walls of the compartments, to provide a larger area thatwill be penetrated as described below. In an alternative, equallyeffective embodiment, second compartment 13 can be a separate containerinside first compartment 11.

Also provided is an opening member 17, shown mounted on the secondcompartment 13, on the end 19 of compartment 13 away from divider 15.Opening member has threads 17 a that will hold an optional cap, notshown. End 19 is not in communication with the inside of compartment 13.Compartment 13 also has an end 21 remote from divider 15. In a preferredembodiment, the junction 23 of the side of compartment 13 and itsbottom, 21, are curved as shown in FIG. 1. This prevents accumulation ofcomponents in compartment 13 from collecting in the corners where accessto them is limited by their being accumulated in the square corners.

Inside compartment 13 is a quantity of heat generating material 25 thatwill undergo a chemical reaction and generate heat when contacted by anactivation material, such as material 27 inside compartment 13. Anaccess element 29, shown in FIG. 4, is designed to fit into openingmember 17 and penetrate divider 15. Penetration of divider 15 will causethe activation material 27 to admix with the heat generating material 25to generate heat. In the following figures, reference is made to heatgenerating material 25 and activation material 27, which are shown herein FIG. 1 and not shown in the remaining figures for purposes ofsimplicity. These two reaction agents are present in the chambers asdescribed below.

FIG. 2 shows the back of device 10, which, in a preferred embodiment,includes a nonwoven material back 31 with a tab 33 that can be used tofasten device 10 to an object to be heated. One side 35 of device 10 isopen after initial manufacture and is sealed after the heat generatingmaterial 25 and activation material 27 in chambers 13 and 11respectively.

FIG. 3 illustrates device 10 in section with upper chamber 11 and lowerchamber 13 in position to hold the activation material 27 and heatgenerating material 25 as described above. Divider 15 is shown as beingattached to the side walls of chamber 11 at 15 a and 15 b, and extendingdown to its lowest point 15 c. Low point 15 c is in the middle of thewidth of chambers 11 and 13, so that the activation material 27 inchamber 11 is near low point 15 c when the device 10 is upright as shownin the figures. To activate device 10, divider 15 is opened to permitthe activation material 27 flow into chamber 13 and react with heatgenerating material 25.

FIG. 4 illustrates preferred access element 29 that has a circular crosssection over it's entire length. Access element 29 also includes acentral bore 41 that extends nearly the full length thereof. Accesselement 29 includes a conically tapered tip 43 that is capable ofpenetrating divider 15 when pressed against it, such as lowest point 15c. At the other end of access element 29 is a head portion 45 of a firstdiameter d₁ that tapers at chamfer 47 to the diameter of the body 49 ofaccess element 29 with a diameter d₂ at taper 43 and along the entirelength of body 49 up to chamfer 47. Central bore 41 thus extends fromsolid tip 43 to head portion 45.

Body 49 has a first slot 51 that functions to transfer activationmaterial 27 through it to enter compartment 13 and react with heatgenerating material 25, as described below.

Body 49 has a second slot 53 that functions to allow steam or othergasses generated in compartment 13 during the reaction of heatgenerating material 25 with activation material 27 to travel up body 49and into upper chamber 11 to exit through opening member 17 throughexhaust hole 55.

FIGS. 5 and 6 illustrate the use of access element 29 in device 10. FIG.5 illustrates device 10 before activation and FIG. 6 illustrates device10 after activation.

In FIG. 5, access element 29 is inserted into opening member 17 andpositioned above hole 55 that is sealed by membrane 57. At this point,heat generating material 25 is isolated from activation material 37. Aninsulating layer 31 is located on the back side of device 10 and theother side is not insulated, so the heat generated will go through thefront or not insulated side of FIG. 1.

In FIG. 6, access element 29 has been fully inserted into device 10,rupturing or penetrating membrane 57 and further extending down topuncture the lower end 15 c of divider 15. At this point, the activationagent 27, not shown for simplicity but shown in FIG. 1, passes throughfirst slot 51 from chamber 11 into chamber 13, and begins to react withheat generating material 25, again shown in FIG. 1. Heat generatingreactions such as those describe below and contemplated for device 10will generate steam or other gaseous byproducts. The reaction, at point61 in chamber 13, generates gas or steam that flows from the reactionpoint 61 into first slot 51, up central bore 41, through second slot 53and into chamber 11. If the pressure in chamber 11 increases, the steamor gas may also flow up central bore 41 and out hole 55. Because the end45 of access element 29 is recessed in opening member 17, the steam doesnot directly heat anything that might adversely affect someone usingdevice 10. Arrow 63 describes generally the path of the steam.

In operation, referring again to FIGS. 1 and 2, an object to be heated,71 in FIG. 7, is placed on the front face of device 10 shown in FIG. 1.In a preferred embodiment, object 71 is about ½ the size of device 10,so that device 10 can be folded to put object 71 in contact with bothhalves of the front of device 10. The folded device 10 is then securedby placing tab 33 in attaching contact with back 31. In a preferredembodiment, tab 33 has a look and latch element that engages nonwovenback 31 to thus hold object 71 in contact with device 10. When it isdesired to heat object 71, access element 29 is inserted into device 10to function as described above and generate sufficient heat to achievethe desired temperature.

The preferred activating material of this invention is water. This isplentiful and safe, and reacts with a number of materials to produce anexothermic reaction. The activating material may include a small amountof an added liquid chemical that extends the time that water can holdthe heat once it is generated. Ethylene glycol is a preferred liquidchemical heat holding agent. The amount of ethylene glycol may rangefrom about 0.2% by weight to about 2.0% by weight, the percentages beingbased upon the weight of the water.

The preferred heat generating material is a solid formed from severalcomponents that, when free from moisture, are stable for up to three tofive years or more, and which react when moisture is present to generateheat. The preferred solid is made from crystalline calcium oxide, azeolite powder, and a polyalkyl glycol such as polyethylene glycol. Theamount of activation material, such as water, is preferably from about75 to 125 weight percent, based upon the total weight of heat generatingmaterial. Approximately equal amounts by weight of water and heatgenerating material is the preferred ratio of these reaction components.

The amount of calcium oxide ranges from about 30 to 70 weight percent,the amount of polyethylene glycol ranges from about 15 to about 35weight percent, and the amount of zeolite ranges from about 15 to about35 weight percent, based on the total weight of heat generatingmaterial. Preferred is about 25 weight percent each of the polyethyleneglycol and zeolite and about 50 weight percent calcium oxide.

The heat generation material most preferred, using the above componentsincludes a calcined calcium oxide. This material is available as a smallparticle size, with a diameter less than about 0.2 mm, and as a particleof somewhere between 0.2 and 0.8 mm. Larger particles are ground andsmaller ones sieved, and the calcium oxide is then calcined. It has beenfound to be effective to calcine for at least 60 to 120 minutes, andpreferably about 90 minutes, at temperatures above 500° C., and mostpreferably at about 550° C. for that period of time. The calcinedcalcium oxide is, of course, desiccated to prevent any contamination bymoisture.

More than 150 zeolite types have been synthesized and 48 naturallyoccurring zeolites are known. They are basically hydratedalumino-silicate minerals with an “open” structure that can accommodatea wide variety of positive ions, such as Na+, K+, Ca₂+, Mg₂+ and others.These positive ions are rather loosely held and can readily be exchangedfor others in a contact solution. Some of the more common mineralzeolites are: analcime, chabazite, heulandite, natrolite, phillipsite,and stilbite. An example mineral formula is: Na₂Al₂Si₃O₁₀-16H₂O.Zeolites, by their nature, are finely porous structures that are“hungry” for water and that have the ability to hold heat. In thepresent invention, the activation agent, water in the preferredembodiment, enters into the zeolite pores, trapping the water as it isheated by reacting with the calcium oxide, thus storing heat, providinga longer, more evenly distributed supply of useable heat.

The polyethylene glycol component of the heat generating material isadmixed with the calcium oxide and zeolite and placed in the outercontainer as described above. When the activation agent, water, isintroduced into the heat generating material, the polyethylene glycolcoats the calcium oxide and zeolite, further delaying the exothermicreaction between calcium oxide and water, and adding to the utility ofthis invention.

The heater of this invention has been used to heat products such as MREpackages to 150° F. within 5 minutes and maintained the heat at or above140° F. for 50 minutes. Prior art devices take 12 minutes to reach only140° F. and only hold that temperature for 20 minutes. Thus the food canbe cooked and kept warm for more than enough time to consume it.

Although the present invention has been described with reference topreferred embodiments, workers skilled in the art will recognize thatchanges may be made in form and detail without departing from the spiritand scope of the invention.

1. A heater device for heating objects, comprising: a first compartmenthaving a quantity of heat generating material therein; a secondcompartment having a quantity of activation material therein capable ofactivating the heat generating material upon mutual contact; the firstcompartment and second compartment together being sized to present aheating surface to the object to be heated; a divider positioned in thefirst compartment and extending into the second compartment forming abarrier to maintain separation between the activation material and theheat generating material; an opening member mounted on the devicepositioned in alignment with the barrier of the divider; and an accesselement positionable in the open member and movable into contact withthe barrier of the divider to open the barrier and permit access of theactivation material to the heat generating material to permit a heatgenerating reaction there between.
 2. The device of claim 1, wherein thedevice further includes a heat absorbing material on the device remotefrom the heating surface.
 3. The device of claim 1, wherein the openingmember is a tube mounted on the end of the first compartment.
 4. Thedevice of claim 3, wherein the tube is adapted to have a removable top.5. The device of claim 1, wherein the access element is a longitudinalmember having an axis and a diameter sized to enter the opening memberand having a length sufficient to reach the barrier of the divider,whereby movement of the access element against the barrier opens thebarrier to permit access of the activation material to the heatgenerating material.
 6. The device of claim 5, wherein the accesselement includes a central bore along the axis providing an openingbetween the first and second chamber when positioned inside them.
 7. Thedevice of claim 6, wherein the access element includes an enlargedpressure pad on the opposite end from the end in contact with the secondcompartment, whereby pressure on the pressure pad moves the accesselement along its axis.
 8. The device of claim 7, where the central boreincludes at least one opening transverse to the axis for providingaccess of the activation material to the passage and the firstcompartment.
 9. The device of claim 1, wherein the first compartment isat a lower pressure than the first compartment by an amount sufficientto increase the rate of transfer of the activation material to the heatgenerating material when access is made.
 10. The device of claim 15,device further includes a heat absorbing material on the device remotefrom the heating surface.
 11. The device of claim 18, which furtherincludes an object to be heated and a tab on the heat absorbingmaterial, such that the device is adapted to be folded over the objectso that the heat absorbing material is external to the object and theheating surface is proximate the object, and the tab is adapted tomaintain the folded device with the heating surface proximate theobject.
 12. The device of claim 19, wherein the object is a packagecontaining food to be heated.
 13. A heater device for heating objects,comprising: a first compartment having a quantity of calcium oxidetherein; a second compartment having a quantity of water therein capableof activating the heat generating material upon mutual contact; thefirst compartment and second compartment together being sized to presenta heating surface to the object to be heated; a divider positioned inthe first compartment and extending into the second compartment forminga barrier to maintain separation between the water and the calciumoxide; an opening member mounted on the device positioned in alignmentwith the barrier of the divider; and an access element positionable inthe open member and movable into contact with the barrier of the dividerto open the barrier and permit access of the water to the calcium oxideto permit a heat generating reaction there between, wherein the accesselement is a longitudinal member having an axis and a diameter sized toenter the opening member and having a length sufficient to reach thebarrier of the divider, whereby movement of the access element againstthe barrier opens the barrier to permit access of the water to thecalcium oxide.
 14. The device of claim 13, device further includes aheat absorbing material on the device remote from the heating surface.15. The device of claim 14, which further includes an object to beheated and a tab on the heat absorbing material, such that the device isadapted to be folded over the object so that the heat absorbing materialis external to the object and the heating surface is proximate theobject, and the tab is adapted to maintain the folded device with theheating surface proximate the object.
 16. The device of claim 15,wherein the object is a package containing food to be heated.